Residents in many northern provinces were on Tuesday breathing air containing more than double the country’s official safe limit of PM2.5, particulates of 2.5 micrograms or smaller per cubic metre, according to the daily update from the Pollution Control Department’s website. (

Air in nation’s North is dangerous to breathe
Sky over the area at the foot of Doi Suthep turned brown due to a toxic haze on Tuesday morning, a striking change from the same area’s blue sky on February 5. The photos were taken from the30th Anniversary Building at Chiang Mai University’s Engineering Faculty. // Photo courtesy of Climate Change Data Centre’s Facebook page

For example, the amount of PM2.5 peaked at between 106 and 136 micrograms per cubic metres on air in various districts of Lampang .

Lampang responded to the recent jump in toxicity by closing its Doi Phra Baht forest, currently ravaged by multiple spots of fire, from Tuesday until April. They will set up checkpoints to deny unauthorized access by outsiders who are not involved in fighting the forest fires, according to the resolution of a Lampang meeting of related agencies on Monday afternoon.

The PCD’s method of basing their numbers on averaging the 24-hour levels, resulted in their reporting lower levels of pollution when compared to the real-time basis reports from other sources, such as the Chiang Mai University mobile “Dust Boy” devices and the Chiang Mai Air Quality Health Index (CMAQHI) Centre.


According to PCD, the amount of PM2.5 dust in the North as of 9am was between 28 and 141 micrograms, peaking at 141 micrograms in Phrae’s Muang along with an AQI level of 251. Lampang’s Muang district station cited 106 micrograms of PM2.5 and an AQI of 216, while three stations in Mae Mo district cited 116 micrograms (with an AQI level of 216), 136 micrograms (with an AQI level of 246), and 113 micrograms (with an AQI level of 223), the PCD said. Chiang Mai’s Muang district station cited 77 micrograms of PM2.5 and an AQI level of 168.

The PCD cited PM2.5 in other northern provinces as follows: Tak’s Mae Sot district at 51 micrograms (with an AQI level of 101); Nan’s Muang and Chalerm Phrakiat districts at 64 micrograms (with an AQI level of 134) and 51 micrograms (with an AQI level of 101); Phayao’s Muang district at 54 micrograms (with an AQI level of 109); Lamphun’s Muang district at 71 micrograms (with an AQI level of 152) and Mae Hong Son’s Muang district at 51 micrograms (with an AQI level of 101).

In Chiang Mai, where the sky turned brownish due to haze, the CMAQHI Centre cited Mae Rim and Doi Lo districts as having the province’s PM2.5 peak at 151 and 106 micrograms and with AQI levels at 201 and 177 respectively. Hang Dong district had 99 micrograms of PM2.5 and an AQI level of 173, while Muang district had 73 micrograms and an AQI level of 160, the centre reported.

Chiang Mai provincial authority announced imposition of a 60-day outdoor-burning ban from March 1 to April 30. People giving useful information leading to a culprit’s arrest will get a cash reward of Bt5,000.

In the wake of the haze, the public health authority warned people to wear a facemask during outdoor activities. They also advised members of “vulnerable” groups such as small children, senior citizens, pregnant women and those with chronic ailments to avoid being outdoors. A facemask of N95 standard is needed to filter the tiny PM2.5 particulates.